Ultrasonic testing device

ABSTRACT

An ultrasonic-testing device including four crystals fixed to a member which may be rotated to a variety of positions. Each crystal when vibrated is adapted to emit ultrasonic waves of a frequency different from the other three. One crystal only is selectively vibrated at any given time, and the position of that vibrated crystal, and thus the direction of ultrasonic waves emitted therefrom, may be varied to an extent by rotation of the member to such variety of positions.

"re eal QR 3 I 59 3 a 57 Q 7 3w??? 1* VIII-Irv ulutvu [72] Inventor Ricard W L,0UL,1U1 1 1952 Mesh... 73/71.5 X

763 Taylor Ave, Alameda,Calif.94501 2,602,102 7/1952 Webb v 73/71.5 X{21] Appl. No. 833,085 2,666,862 1/1954 Branson 73/715 X [22) Filed June13, 1969 3,257,843 6/1966 Cowan 73/715 1 Palemed J y 0, 1971 3,423,9931/1969 Lynnworth 73/715 Primary ExaminerRichard C. Queisser 541ULTRASONIC TESTING DEVICE Assistant Examinerc- Snee 4 Claims, 11 DrawingFigs. Attorney-Mdlin, Moore & Weissenberger [52] US. Cl 73/715, m

ABSTRACT: An ultrasonic-testing device including four [51] It ll. Cl 1G011! 29/04 rystals fix d to a member which may be rotated to a variety0 of positions Each cry stal when vibrated is adapted to emit u].

trasonic waves of a frequency different from the other three. Onecrystal only is Tri and [56] Rderences cued Tl'E position of thatvibrated crystalsand thus the q c ggg g f I UNlTED STATES PATENTSultrasonic waves emitted therefrom, may b e y arieq to an ex- 2,460,1531/1949 Smoluchowski 73/715 X tent by rotation of the member to suchvariety of positions.

&1 s

ULTRASONIC TESTING DEVICE BACKGROUND OF THE INVENTION FIG. 4 is asectional view taken along the line 44 of FIG. 3;

FIG. 5 is a view taken along the line 5-5 of FIG. 3, showing the wiringmeans of the device;

FIGS. 6ll are a series of schematic elevational views ofa This inventionrelates to ultrasonic testing devices, and, 5 Portion of the deviceShowing its general use in lting more particularly, to a device whichmay be adjusted to emit various frequency ultrasonic waves in variousdirections.

Devices which emit ultrasonic waves for purposes of testing materialsfor cracks or flaws are, of course, well known. A typical device of thistype includes a body having fixed thereto a crystal. A series ofelectrical charges are placed on the crystal, causing the crystal tomechanically vibrate and emit ultrasonic waves in a fixed generaldirection relative to the crystal and to the body. 7

In the use of such a device, the body thereofis generally run over thesurface of the object to be tested, with the ultrasonic waves from thecrystal penetrating the materialof the object.

A flaw or discontinuity in the object causes a reflection of theultrasonic beam, and appropriate means, cooperating with the crystalwhich senses the reflection of the beam, are included for noting thepresence and position of such reflection.

Depending on the thickness ofthe object, the material thereof, and thelike, it has been found advantageous to test any given object, or anyvariety of objects, with ultrasonic beams of various frequencies and invarious directions relative to the surface of the object. This isgenerally done by providing a series of separate testing devices, eachhaving a singlefrequency crystal which emits ultrasonic waves in asingle general direction. Obviously, the use of such a series ofseparate testing devices requiring the switching of one for another, isa relatively time-wasting and inconvenient opera tion.

It is an object of this invention toprovide an ultrasonictesting devicewhich is capable of selectively emitting any one of a variety ofultrasonic wave frequencies.

It is a further object of this invention to provide an ultrasonictesting device which, while fulfilling the above object, provides meansfor adjusting the general direction of the illtrasonic waves emittedtherefrom.

It is a still further object of this invention to provide an ultrasonictesting device which, while fulfilling the above objects, is extremelysimple and effective in design and convenient in operation.

SUMMARY OF THE INVENTION Broadly stated, the inventive ultrasonic devicedisclosed herein comprisesa body having a generally cylindrical aperturetherethrough. A generally cylindrical rotatable member is disposed inthe aperture and is positionable relative thereto in a variety ofpositions. A plurality of crystals are fixed to the rotatable member,each adapted to emit ultrasonic waves in-a fixed general directionrelative to itself when vibrated, the rotation of the rotatable membertosuch plurality'of positions varying the general direction of the emittedultrasonic waves from each crystal relative to the body. Furtherincluded is'a slipring comprising a plurality of slipring portions whichare spaced to define a noncontinuous slipring surrounding thecylindrical member. Wire means interconnect each slipring portion with acrystal. Means are positioned to contact the slipring for applying aseries of electrical charges to only the slipring portion thereofcontacted, and the crystal connected thereto, such rotatable memberbeing positionable so that any of the other slipring portions alone maybe contacted by the contacting means.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of theinvention will-become apparent from a study of the followingspecification and I the core 20 material is chosen to ject.

DESCRIPTION OF THE PREFERRED EMBODIMENT Shown generally in FIG. I is theinventive ultrasonic testing device 10. Making up the body 11 of thedevice 10 is an inner plastic member [2 having fixed thereto ultrasonicabsorbent material 14, and a metal cover 16. The member I2 has agenerally cylindrical aperture I8 therethrough.

As shown in detail in FIGS. 3-5, a core 20 has fixed thereto the bottomsurfaces 22A, 24A, 26A, 28A of substantially flat crystals 22, 24, 26,28, in generally perpendicular relation to each other. The end portions20A, 20B of core 20 are generally cylindrical in configuration; Plasticfillers 30, 32, 34,

'36 are fixed to the top surfaces 22B, 248, 268,288 of the crystals 22,24,26, 28 respectively, and these fillers, being of semicylindricalconfiguration, together with the cylindrical fillers 30,32, 34, 36,andcommunicate with the grooves 40,

42. When fitting the member 38 into aperture 18, O -rin'gs (not shown)are fitted into grooves 40, 42, and a suitable liquid, such asglycerine, is applied to the member 38, filling the grooves 44, 46, 48,50. Such liquid provides a thin film between the member 38 and theportion of the member 12 defining the aperture 18. The grooves 44, 46,48, 50 provide a reservoir of liquid, meanwhile allowing space for anyair bubbles about the member 38 to dissipate into.

Surrounding member 38 adjacent end portion 20B is a slipring 52. Suchslipring is made up of four slipring portions or segments 54,56, 58,60of equal lengthwhich are gapped or spaced at 62, 64, 66, 68 to definethe slipring 52in a noncontinuous fashion.

A wire 70 interconnects segment 54 with the bottom surface 24A ofcrystal 24, a wire 72 interconnects segment 56 with the bottom surface26A of crystal 26, a wire 74 interconnects segment 58 with the bottomsurface 28A of crystal 28, and a wire 76 interconnects segment 60 withthe bottom surface 22A of crystal 22. The top surface 22B, 24B, 26B, 28Bof the crystals communicate with a metal plate 78 by means of wires 80,82, 84-, 86 and a metal spring 88 is disposed between metal plate 78'andcover 16 when member 38 is disposed in apertures 18 and cover [6 is inplace. Such means ensure that the top surfaces 22B, 24B, 26B 28B of thecrystals 22, 24, 26, 28 are grounded.

A spring member 90 is positioned in a small bore 92 which communicateswith aperture 18, and contacts a segment of slipring 52. An insulatingcap 94 is included to keep spring member 90 from contacting cover 16. Anelectrical cable 96, connnected to an ultrasonic generator (not shown),communicates with spring member 90 through a neck portion 98 of cover16.

Through spring member 90, a series of electrical charges are applied tothe inner surface of any given crystal, depending on which segment ofthe slipring 52 is contacted by the spring member 90. With'such seriesof charges being applied to one side of the crystal, and the other sideofthe crystal grounded, mechanical vibrations are set up therein so thatultrasonic waves are emitted. Such ultrasonic waves are emitted inopposite fixed general directions relative to that crystal, but

emitted into it.

The emission of such ultrasonic waves from a crystal is shown generallyin FIG. 6. Therein, spring member 90 contacts segment 54, causingcrystal26 to vibrate, emitting ulabsorb the waves being trasonic waves in thegeneral direction A. The absorbent material 14 absorbs internal wavereflections induced by crystal 26, and the cover [6 acts as a shieldagainst stray electrical radiation. An object 100 may be tested forflaws or discontinuities by running the device over the surface 100A ofthe object 100, the thin liquid film previously described providingcontinuity between the member 38 and plastic member 12. The ultrasonicwaves enter the object 100 and are reflected by a flaw or discontinuity,which may be noted, as is well known.

if it is desired to have the ultrasonic waves from crystal 26 enter theobject 100 at a chosen angle of, for example, 30 member 38 is rotatedclockwiseby means of a knob 39 extending through an aperture 104 in thecover 16, which varies the general direction A of the emitted ultrasonicwaves relative to the body [0 (H6. 7). As shown in FIG. I, pointers 102,104, 106, 108 may be fixed to the knob 39 to indicate on a scale 110 thecrystal which is emitting the ultrasonic waves, and the position of thatcrystal relative to the body 10.

Upon such 30 rotation, segment 54 is still in contact with spring member90, and so only crystal 26 is activated (FIG. 7). The ultrasonic wavestherefrom enter the object 100 at an angle of 30.

FIGS. 7, 8 and 9 show the member 38 having been rotated to otherpositions, so that the ultrasonic waves enter the object 100 at anglesof 4560", and 70. When the member 38 is rotated 90 from its positionshown in FIG. 6, segment 54 no longer contacts spring member 90, butrather segment 60, causing crystal 24 to vibrate. It will be seen thatsuch member 38 may, of course, be rotated to various positions so that achosen crystal emits ultrasonic waves in a chosen general directionrelative to the body 10. By choosing each crystal to emit its ownfrequency different from the others, one can accomplish not onlyvariation of the angle of the emitted ultrasonic waves, but alsovariation from crystal to crystal of the frequency of the emittedultrasonic waves.

Any one of four frequencies may be easily chosen to suit the material ofthe object being tested, and any angle between 0 and 90 for each ofthese frequencies may be easily chosen to suit the configuration andmaterial of the object being tested.

Such changes of frequency and angle are achieved by simple rotation ofmember 38 by means of knob 39. it will be seen that the device, overall,is extremely simple and effective in design, and convenient inoperation.

lclaim:

1. An ultrasonic device comprising:

a. a body having a generally cylindrical therethrough;

aperture b. a generally cylindrical rotatable member disposed in theaperture and positionable relative thereto in a variety of positions;

c. a plurality of crystals fixed to the rotatable member, each adaptedto emit ultrasonic waves in a fixed general direction relative to itselfwhen vibrated, thg gtation of the rotatable member to such plurality ofpositio rylEEiDEJQELELQ WQ iQH 9 m ul r e av' s from each crystalrelative to the body;

d. a slipring comprising a plurality of slipring portions which arespaced to define a noncontinuous slipring surrounding the cylindricalmember;

e. wire means interconnecting each slipring portion with a crystal;

means positioned to contact the slipring for applying a series ofelectrical charges to only the slipring portion thereof contacted, andthe crystal connected thereto, such rotatable member being positionableto vary the general direction of the emitted ultrasonic waves from thatcrystal relative to the body and further being positionable so that anyof the other slipring portions alone may be contacted by the contactingmeans.

2. A device according to claim I wherein are further included pointermeans fixed to the cylindrical member and extending therefrom andpositioned to indicate the position of the rotatable member relative tothe body.

3. A device according to claim 2 wherein IS included a liquid film aboutthe cylindrical member in the aperture.

4. An ultrasonic device comprising;

a. a body having a generally cylindrical thcrethrough;

b. a generally cylindrical rotatable member disposed in the aperture andpositionable relative thereto in a variety of positions;

a plurality of crystals fixed to the rotatable member, each adapted toemit ultrasonic waves in a fixed general direction relative to itselfwhen vibrated, the rotation of the rotatable member to such plurality ofpositions varying the general direction of the emitted ultrasonic wavesfrom each crystal relative to the body, each of said crystals having afrequency of vibration different from the others; d. means forconnecting a preselected one of said crystals to, and disconnecting theremainder of said crystals from,

a source of electrical energization throughout a predetermined range ofrotation of said rotatable member relative to said body.

aperture

1. An ultrasonic device comprising: a. a body having a generallycylindrical aperture therethrough; b. a generally cylindrical rotatablemember disposed in the aperture and positionable relative thereto in avariety of positions; c. a plurality of crystals fixed to the rotatablemember, each adapted to emit ultrasonic wavEs in a fixed generaldirection relative to itself when vibrated, the rotation of therotatable member to such plurality of positions varying the generaldirection of the emitted ultrasonic waves from each crystal relative tothe body; d. a slipring comprising a plurality of slipring portionswhich are spaced to define a noncontinuous slipring surrounding thecylindrical member; e. wire means interconnecting each slipring portionwith a crystal; f. means positioned to contact the slipring for applyinga series of electrical charges to only the slipring portion thereofcontacted, and the crystal connected thereto, such rotatable memberbeing positionable to vary the general direction of the emittedultrasonic waves from that crystal relative to the body and furtherbeing positionable so that any of the other slipring portions alone maybe contacted by the contacting means.
 2. A device according to claim 1wherein are further included pointer means fixed to the cylindricalmember and extending therefrom and positioned to indicate the positionof the rotatable member relative to the body.
 3. A device according toclaim 2 wherein is included a liquid film about the cylindrical memberin the aperture.
 4. An ultrasonic device comprising; a. a body having agenerally cylindrical aperture therethrough; b. a generally cylindricalrotatable member disposed in the aperture and positionable relativethereto in a variety of positions; c. a plurality of crystals fixed tothe rotatable member, each adapted to emit ultrasonic waves in a fixedgeneral direction relative to itself when vibrated, the rotation of therotatable member to such plurality of positions varying the generaldirection of the emitted ultrasonic waves from each crystal relative tothe body, each of said crystals having a frequency of vibrationdifferent from the others; d. means for connecting a preselected one ofsaid crystals to, and disconnecting the remainder of said crystals from,a source of electrical energization throughout a predetermined range ofrotation of said rotatable member relative to said body.